I've got a 99 Z28, with a Hot Cam, long tubes, Borla, Pulley, LS6 manifold.

I had it dyno tuned, but the shop is now out of business and I think their tune may have been crap. I have removed my AIR system and EGR as well. I'm running O2 sims in the rear and some Denso O2's up front.

The car stinks. Like, burn your eyes out of your head stink. According to the scanmaster, its always adding fuel. I think the last time I drove it the LT trims were positive 5 and positive 7. Pretty sure that's where they were.

When I bought the exhaust, I thought ahead and got a system, FLP, that had interchangeable cats and straight pipes.

So the question is, if I do nothing but put the cats in, and leave everything else alone, will my stink go away? Or, do I need to run the EGR and AIR if I'm going to run cats?

Secondly, could the stink be eliminated by a better tune? The car is so lightly modified, that I'm sure a mail in tune would be just as good as a dyno tune. I did all this stuff back when things were kind of in their infancy regarding these cars and engines.

Now I'm at a point in my life, where being loud and fast are only so important. Getting rid of the stink is more important.

Thanks

 

Running rich

 

dyno tunes = WOT tune. you need a street tune

 

do you have a off road y it will probably stink cause of that with the cam

 

that cam is pretty mild

 

Yes I have a offroad Y, if you mean the one that came with the FLP header package. I don't have any cats installed, but high flow ones came with the headers and can be dropped right in, but the AIR and EGR is disconnected. Probably need a tune like the guy above said.

 

no cats= smelly car

 

So, then the question is, can I hook up the cats without having the EGR or AIR hooked up? That would be the ideal situation.

 

I don't see why not, that's what I'm doing.
And no more burn your eyes out smell!

 

i have no cats and i definitely don't have the burn your eyes out smell

 

It could use some TLC on the street side of the tune. Positive trims are a bad thing as the pcm will actually add the + trim to the wot fueling but 5-7 is not horrible.. the last car I scanned was 22 even pegging 25 in some cells now that is wayyy off.

regardless though no cats = smell.

 

I mentioned this in another post tonight, but I have cats and still the smell. I was looking for posts on results of adding the AIR system back. I think the cats helped some, but I am looking to make it better.

 

I've decided that I'm going to send my PCM to Frost at LSXtune for a street tune, instead of the WOT tune that is currently in place. Based on the results of that, I may install the high flow cats, but I'm not going to install the AIR or EGR. I'll live with the stink before I put hose ugly tubes back on the engine.

 

I believe AIR is only used at start up to get the cats to heat up quicker so they can start cleaning up the exhaust faster - reduces emissions at start up. Once the car is warmed up AIR doesn't do anything.

 

If the smell feels like its gonna burn your eyes youre running lean...

 

switching between +10 / -10 is fairly normal. Thats not bad at all. Ive seen in the 20's and 30's now that is way off. +5 or +7 is not bad. And I believe your running lean.

 

I hope I never get to that point...